Processing of photographic material



Nov. 29, 1960 E. R. TOWNLEY ETAL ,96 ,9

PROCESSING OF PHOTOGRAPHIG MATERIAL Filed Feb. 27, 1957 3 Sheets-Sheet 2 IN l/E N T025 A TTORNE Y5 Nov. 29, 1960 E. R. TOWNLEY ETAL 8 PROCESSING OF PHOTOGRAPHIC MATERIAL Filed Feb. 27, 1957 3 Sheets-Sheet 3 INVENTORS' ATTORNEXj U ited States Patent 2,961,938 PROCESSING OF PHOTOGRAPHIC MATERIAL Eustace R. Townley and Harold L. Frost, Barkingside,

England, assignors to Kelvin & Hughes Limited, Glasgow, Scotland, a British company Filed Feb. 27, 1957, Ser. No. 642,698

Claims priority, application Great Britain Mar. 2, 1956 7 Claims. (Cl. 95-89) The present invention relates to the processing of photographic material and is particularly, although not exclusively, concerned with apparatus adapted to photograph, process, and project pictures from the processed material within a short time interval.

The invention is especially. concerned with apparatus adapted to photograph a cathode ray tube trace and to give a high quality, fully-processed projected picture within a very short time, and has specific reference to the processing means employed in apparatus of this kind.

An important object of the invention is to provide apparatus for processing photographic material in which the processing time can be reduced for a given quality of the product.

Processing methods are already known in which photographic light sensitive material is processed by the appli- A 2,961,938 Patented Nov. 29, 1960 ICC however, the jets are all arranged to operate upon the I 7 material in a single station, the material being held stacation of suitable liquids in processing cups or dishes or by means of sprays. All the methods hitherto used have suffered from two main disadvantages.

(a) The formation of contamination deposits in the liquid supply lines caused by the interaction of the processing liquids and (b) The plating-out of silver in the supply lines and in the processing dishes caused by the interaction of the spent processing liquids.

It is a further object of this invention to enable these disadvantages to be overcome or substantially reduced and to provide improved apparatus which can be used in the production of either positive or negative pictures.

It is a subsidiary object of the invention to provide apparatus in which, in the case of failure anywhere in the photographic-processor-projector apparatus, no liquids flow and air continues to flow over the photographic light sensitive material being processed.

According to the present invention there is provided apparatus for the processing of photographic material comprising at least one jet having a liquid supply line and an air supply line so arranged that compressed air in the air supply line is adapted to draw liquid along the liquid supply line and eject the liquid in a fine spray from the jet, and an electro-magnetically-operated valve in the air supply line.

In a preferred form of the invention a plurality of the said jets is provided and an electro-magnetically-operated valve is provided in the air supply line to each jet. Since each liquid supply line carries only one liquid, interaction between diiferent liquids in the supply lines is avoided. Moreover the avoidance of the need for valves in the liquid supply lines avoids difliculties arising from the corrosion of such valves.

A further jet connected to a source of compressed air by an air supply line containing a further electromagnetically-operated valve is preferably provided. Means may be provided for heating the air supply thus raising the processing temperature. This feature is parrapidly at an elevated temperature.

tionary in this station for the appropriate time.

The invention will be described by way of example with reference to the accompanying drawings in which:

Fig. 1 is a diagrammatic representation of one embodiment of the invention,

Fig. 2 is a perspective view of a jet assembly for use in the embodiment,

Fig. 3 is a cross-sectional view of one of the jets in Fig. 2,

Fig. 4 is a diagram showing the mode of operation of the electro-magnetically-operated valves in the embodiment,

Fig. 5 is a perspective view of cam-operated switches used in the embodiment, and

Figs. 6 and 7 show the shapes of cams used in Fig. 4.

The embodiment to be described is an apparatus for the photographing, processing and projection of radar images appearing on the screen of a cathode ray tube. In this apparatus the photographing, processing and projection are all carried out in synchronism with the aerial scan of the radar apparatus.

Referring to Fig. 1, the trace on a cathode ray tube 10 is photographed on film 11 which remains stationary in the camera 12, represented by a lens 13 and shutter 14, in the exposure position, e.g. for the time taken for the radar aerial to make one complete rotation. It is then passed, in the direction of the arrow 19, from the camera to the processing station 15, where it again remains for the same period whilst a new picture is taken at the exposure station. From the processing station the film passes on to the projection station 16, shown as including a light source 17 and a projection lens 18, and the projected image is presented on a screen (not shown);

Certain features of this apparatus, including the means for advancing the film, form the subject of patent application No. 642,697 filed February 27, 1957, now Patent No. 2,927,790, and are described in the specification of that application. The present description will, therefore, be confined to that part of the apparatus which is concerned with the processing of the film.

In the processing station 15, the film frame to be processed lies over a chamber 20 from which spent liquid is discharged through a waste line 21. The frame of the film 11, which is stationary in the processing station is shown in Fig. 1 as being supported by the upper surfaces of the walls of chamber 20. Four jets, of which only one marked 22a is shown in Fig. l, are arranged within the chamber 20.

Referring to Fig. 2, the jet assembly is a unitary structure comprising a base 23 through which are sealed pipes 24 supporting jets 22a, 22b and 220, and a further centrally-disposed jet 25. The three jets 22a, 22b and 220 are suitably inclined relatively to one another in such a manner that each is directed at the centre of the film frame.

Referring again to Fig. 1, each of the three jets 22a, 22b and 220 of Fig. 2 is coupled by a separate supply line 25 to a reservoir 26 fora difierent liquid, namely in this example developer, fixer, and water, and by a separate supply line 27 through an air heater 28 and an electro-magnetically-operated valve 29 to a source of compressed air, such as a compressor, which is not shown. Only one of the reservoirs 26 is shown in Fig. 1.

Each jet 22a, 22b and 22c is constructed as shown in Fig. 3, and comprises a miniature Venturi system Compressed air is fed through a pipe 24' and a pipe 24" is connected with the liquid supply line 25. The drop in pressure in the jet chamber 30 causes a rise of liquid from the pipe 24" into this chamber. The compressed air fed down the air supply line thus results in liquid being sucked into the mixing chamber 30 of the jet where it is atomized and sprayed on to the film at high velocity.

The fourth jet 25 (Fig. 2) is connected to the source of compressed air and heating means are provided for this air also.

A solenoid-operated valve 29 as shown in Fig. 1 is provided in each of the air supply lines and the operation of these valves is controlled by a cam switch sysstem 31 to be described later. This system also controls a solenoid-operated film-crimper 32 which may be constructed in accordance with British patent specification No. 764,970 and serves the purpose set forth in that specification.

Fig. 4 shows the arrangement of the three solenoidoperated valves 29a, 29b and 29c serving to control the .air supply to the nozzles 22a, 22b and 22c respectively of Fig. 2 and a solenoid-operated valve 34 serving to control the air supply to the nozzle 25 of Fig. 2.

The valves 29a, 29b and 290 are alike and each comprises a solenoid Winding 35 having a core 36 of magnetic material projecting within it, the core being biased downward by a spring 37 and thus maintaining the valve 38 normally closed. Switches 39a, 39b and 390 control the supply of current to the windings 35 from a source shown as a battery 40. When a winding 35 is energised, the associated valve 38 is opened against the action of the spring 37.

The valve 34 operates in the opposite manner, that is to say, it is normally held open by its spring 41. The

upper half 42 of the core is of magnetic material and the lower half 43 of the core is of non-magnetic material and energising of the winding 44 by closure of a switch 45 closes the valve.

The valves 29a, 29b and 290 control the supply of compressed air from a source connected at 46 to the air supply lines 27a, 27b and 27c respectively of the nozzles 22a, 22b and 220 respectively of Fig. 2. Air supply to the nozzle 25 of Fig. 2 through a supply line 47 is controlled by the valve 34.

The switches 39a, 39b, 39c and 45 of Fig. 4 are operated in proper sequence by means of a multiple cam switching device part of which is shown in Fig. 5.

The shaft 47 of the device is driven by a servo motor (not shown) in synchronism with the rotation of a radar aerial and makes one rotation for each rotation of the aerial.

The switches 39a, 39b and 390 are operated by a pair of like cams 48 and 49 offset relatively to one another about the shaft axis, the cam 48 serving to open the switches and the cam 49 serving to close them. The cams have the shape shown in Fig. 6 and proceeding from a step 50 in the direction of movement of the blade over the cam indicated by the arrow 51', have a portion A extending over 135 of dwell at the smaller radius, a portion B extending over 100 of rise, and a portion C extending over 125 of dwell at the larger radius.

Each switch comprises two blades 52 and 53 engaging the cams 48 and 49 respectively. When both blades dwell in their outer position the contact at 54 is broken. When the blade 53 reaches the step 50 on its cam 49 it moves inwards and makes the contact. When the blade 52 reaches the step 50 in its cam 48 this blade moves inwards and breaks the contact. The use of the double cam ensures rapid making and breaking of the switches.

Bolts 54 passing through slots 55 and securing the '4 cams to the shaft 47 enable the positions of the cams to be adjusted.

The switch of Fig. 4 is operated by a second pan of earns 56, 57 of the same shape as the cams 48 and 49 and cooperating with blades 58 and 59. In this case, however, the cams are so displaced relatively to one another that the step in the upper cam 56 leads that in the lower cam 57.

A cam switch 60 identical with 45 serves to operate the film-crimper 32 and the shutter 14 of Fig. 1.

A single cam switch 61 is provided for operating the fihn-advancing mechanism. The switch 61 has a camoperated blade 62 co-operating with two fixed blades 63 and 64. When the blade 62 is in its outermost position it makes contact with 63 and applies a charge to a capacitor. When the blade 62 reaches the step and snaps inward it makes contact with the blade 64 thereby discharging the capacitor through an electromagnetic device controlling the film advance. This is fully described in the specification of Patent 2,927,790 hereinbefore referred to.

The cam of the film-advancing switch 61 has the shape shown in Fig. 7. After the step 65 there is a dwell D at the smaller radius of 30 followed by a rise to a larger radius extending over the are E of and finally a dwell F of 230.

The-sequence of switching of the switches 45, 29a, 29b and 290, beginning with the moment of arrival of a film frame in the processing chamber, is as follows:

(1) The switch 45 is closed, thereby shutting olf the supply of hot air, and the switch 29a is closed thereby spraying developer on to the frame;

(2) The switch 45 remains closed, the switch 29a is opened, and the switch 29b is closed;

(3) The switch 45 remains closed, the switch 29b is opened and the switch 290 is closed;

(4) The switch 290 is opened and the switch 45 is also opened and remains open throughout the remainder of the cycle of operation.

The angular displacement of the earns 48 and 49 relatively to one another is adjusted to give a make period of 82. The cams 56 and 57 are displaced to the same extent but with the cam 56 leading the cam 57 by 82,

so that in this case the switch is opened for 82.

The relative orientation of the various cams in Fig. 5 is such that the switch 45 opens (and turns on the drying air) at the same time as the wash switch 390 opens (and turns off the supply of water). The switch 60 serving to open theshutter 14 (Fig. 1) and actuate the crimping solenoid 32 closes about 1 after the switch 45 closes and remains closed for 7.2". The inward movement of the blade 62 of switch 61, which initiates the advance of the film, is arranged to occur l.25 after the closure of the switch 60.

The film being processed may be in any attitude and not necessarily in a horizontal plane as shown.

In the apparatus described there are three principal possible causes of breakdown i.e., breakdown may be caused by aerial failure, by mechanical jamming anywhere in the system, or by a power failure. In order to ensure that in the event of any of these failures occurring, all liquids should cease to flow but that air should continue to flow, there may be provided a relay amplifier which receives signals from a feed-back generator in the servo motor circuit coupling the aerial to a motor driving the cam switch shaft and which actuates a relay having contacts in series with each of the cam switches. 50 long as the apparatus is working satisfactorily, the feedback generator supplies signals to the amplifier and so maintains the relay operated with its contacts closed, but as soon as failure occurs anywhere in the system, no signal is fed to the amplifier, the relay releases and thus the valves in the develop, fix and wash air lines remain closed whilst that in the air dry line remains open.

An additional safeguard is provided in the apparatus described in that in the absence of current in the solenoids the valves 29a, 29b, 29c controlling liquid supply remain closed while the valve 34 controlling the hot air supply remains open.

In the apparatus described, the processing liquids never mix until the waste stage and as the waste line is separate from the supply lines, there is no danger of silver plating out in the supply lines.

As there is no switching in the liquid supply lines, no valves or moving parts are required in these lines and thus one corrosion problem which is always present in known apparatus is removed.

The electromagnetic switching of the air lines ensures the rapid transient application of the liquids to the material being processed. In other words, the processing liquids are applied in sharp blasts and there is no danger of staining which would arise, for instance, if a small quantity of fixer were allowed to interact with the developer before the main supply of fixer was applied.

It is usually desirable to locate the jet unit at an appreciable distance away from the material being processed. This has the advantage of increasing the uniformity of processing and also removes the dangers of contamination caused by waste liquids clogging the surface of the material being processed and the mouths of the supply jets.

In the case where a combined develop-fix solution is used only one liquid-supplying jet need be used.

We claim:

1. In combination in apparatus for the rapid processing of photographic material, means for supporting said material, a liquid delivering jet positioned to direct liquid upon said material, a reservoir of liquid, a source of compressed air, a liquid supply line coupling said jet to said reservoir, an air supply line coupling said jet to said source, air from said source ejecting liquid from said reservoir through said jet, an air delivering jet positioned to direct air upon said material, a further air supply line coupling said air delivering jet to said source, and an electromagnetically-operated valve in each said air supply line, the valve in the first-named air supply line comprising spring means maintaining the last-named valve normally closed and a solenoid for opening the lastnamed valve against said spring means, and the valve in said further air supply line comprising spring means maintaining the last-named valve normally open and a solenoid for closing the last-named valve against the action of the last-named spring means.

2. In combination in apparatus for the rapid processing of photographic material, means for supporting said material, a liquid delivering jet positioned to direct liquid upon said material, a reservoir of liquid, a source of compressed air, a liquid supply line coupling said jet to said reservoir, an air supply line coupling said jet to said source, air from said source. ejecting liquid from said reservoir through said jet, an air delivering jet positioned to direct air upon said material, a further air supply line coupling said air delivering jet to said source, an electromagnetically-operated valve in each said air supply line, the valve in the first-named air supply line comprising spring means maintaining the last-named valve normally closed and a solenoid for opening the last-named valve against said spring means, and the valve in said further air supply line comprising spring means maintaining the last-named valve normally open and a solenoid for closing the last-named valve against the action of the lastnamed spring means, a source of current, switch means including two switches operated in succession at predetermined intervals, and means coupling each said solenoid to said source of current through one of said switches.

3. Apparatus according to claim 2 wherein said switch means comprises a cam and means for rotating said cam, said switches being positioned to be opened and closed in succession by said cam.

4. Apparatus for the processing of photographic material comprising means for supporting said material in a stationary position in a processing station, a plurality of liquid delivering jets disposed to direct liquid in a spray upon the same area of said processing station, a plurality of reservoirs for'processing liquids, a liquid supply line coupling each said reservoir to a different one of said jets, a source of compressed air, air supply lines coupling said source to each of said jets, the compressed air expelling liquid from said reservoirs through said jets upon said material, an electromagnetically-operated valve in each said air supply line, and switching means coupled to said valves to operate said valves in succession, each said valve comprising resilient means maintaining said valve normally closed and electro-magnetic means re sponsive to closure of said switching means to open said valve.

5. Apparatus according to claim 4, comprising heating means in at least one of said air supply lines.

6. Apparatus for the processing of photographic material comprising means for supporting said material in a stationary position in a processing station, a plurality of liquid delivering jets disposed to direct liquid in a spray upon the same area of said processing station, a plurality of reservoirs for processing liquids, a liquid supply line coupling each said reservoir to a diiferent one of said jets, a source of compressed air, air supply lines coupling said source to each of said jets, the compressed air expelling liquid from said reservoirs through said jets upon said material, a further jet directed upon said area of said processing station, a further air supply line coupling said further jet to said source whereby air is blown from said further jet upon said material, an electromagnetically-operated valve in each said air supply line, and switching means coupled to said valves to operate said valves in succession.

7. Apparatus according to claim 6, comprising heating means in at least one of said air supply lines.

References Cited in the file of this patent UNITED STATES PATENTS 2,446,668 Tuttle et a1 Aug. 10, 1948 2,476,007 Tuttle et al July 12, 1949 2,540,124 Klein Feb. 6, 1951 2,574,762 Schell Nov. 13, 1951 2,615,470 Bickley Oct. 28, 1952 2,631,511 Tuttle Mar. 17, 1953 2,688,278 Tuttle Sept. 7, 1954 2,760,418 Hawn Aug. 26, 1956 FOREIGN PATENTS 589,453 Germany Dec. 7, 1933 

